Injection controller

Abstract

An injection controller includes a control IC outputting an energization instruction signal to apply a peak current to a fuel injection valve (i.e., an instruction TQ), and a current monitor unit detecting an electric current flowing in the fuel injection valve. The control IC corrects an output OFF time of the energization instruction signal based on a difference between (i) an integrated current of an ideal current profile which serves as a target current before reaching the peak current and (ii) an integrated current of an energization current in the fuel injection valve detected by the current monitor unit (i.e., an effective TQ).

What is claimed is: 
     
       1. An injection controller that injects fuel from a fuel injection valve, the injection controller comprising:
 a control unit configured to output an energization instruction signal for controlling the fuel injection valve; and 
 a current detector configured to detect an electric current flowing in the fuel injection valve, 
 wherein 
 the control unit corrects an output OFF time of the energization instruction signal based on a difference between (i) an integrated current of an ideal current profile and (ii) an integrated current of the detected current detected by the current detector, and 
 the integrated current of the ideal current profile is a first ideal charge amount flowing into the fuel injection valve during a first continuous time period within a single ideal fuel injection cycle. 
 
     
     
       2. The injection controller of  claim 1 , further comprising:
 a reach time detection unit configured to detect a reach time of the detected current detected by the current detector for reaching a predetermined current threshold, wherein 
 the control unit corrects the output OFF time based on the reach time and the predetermined current threshold. 
 
     
     
       3. The injection controller of  claim 2 , wherein
 the control unit corrects the output OFF time of the energization instruction time with reference to a reference value of the energization instruction time determined based on the reach time. 
 
     
     
       4. The injection controller of  claim 2 , wherein
 a peak current estimation unit is configured to estimate a peak current estimated value based on the reach time of the detected current for reaching the predetermined current threshold, wherein 
 the control unit corrects the output OFF time of the energization instruction signal so that a post-correction integrated current after correction of the energization instruction signal based on the peak current estimated value becomes equal to the integrated current of the ideal current profile. 
 
     
     
       5. The injection controller of  claim 1 , wherein
 the control unit corrects the output OFF time of the energization instruction signal based on a difference of the integrated currents up to a plurality of reach times for reaching a plurality of current thresholds. 
 
     
     
       6. The injection controller of  claim 5 , further comprising:
 a peak current estimation unit configured to estimate a peak current estimated value based on the plurality of reach times of the detected current for reaching the plurality of current thresholds, wherein 
 the control unit corrects the output OFF time of the energization instruction signal by calculating a correction time during a period from a reach time when the energization current of the fuel injection valve lastly reaches a current threshold among the plurality of the current thresholds to a subsequent reach time when the energization current of the fuel injection valve reaches the peak current estimated value. 
 
     
     
       7. The injection controller of  claim 5 , further comprising:
 a peak current estimation unit configured to estimate a peak current estimated value based on the plurality of reach times of the detected current for reaching the plurality of current thresholds, wherein 
 the control unit corrects the output OFF time of the energization instruction signal so that a post-correction integrated current after correction of the energization instruction signal based on the peak current estimated value becomes equal to the integrated current of the ideal current profile. 
 
     
     
       8. The injection controller of  claim 1 , wherein
 the control unit determines whether the energization current of the fuel injection valve has reached the peak current of the ideal current profile, and switches a correction time of the output OFF time in a stepwise manner based on a determination result regarding the reaching of the peak current. 
 
     
     
       9. The injection controller of  claim 1 , wherein
 the control unit determines whether a predetermined time has lapsed from an output of the energization instruction signal, and switches a correction time of the output OFF time in a stepwise manner based on a determination result regarding the lapse of the predetermined time. 
 
     
     
       10. The injection controller of  claim 1 , further comprising:
 a boost voltage detection unit configured to detect a boost voltage applied to the fuel injection valve at an injection start timing, wherein 
 the control unit compares the boost voltage detected by the boost voltage detection unit at the injection start timing with a boost voltage reference value, and performs correction on a condition that the detected boost voltage is lower than the boost voltage reference value or does not perform correction on a condition that the detected boost voltage is equal to or higher than the boost voltage reference value. 
 
     
     
       11. The injection controller of  claim 1 , wherein
 the integrated current of the ideal current profile is ∫ t0   ta (PI)dt, 
 t 0  is an ideal energization start time, 
 ta is an ideal energization end time, and 
 PI is the ideal current profile. 
 
     
     
       12. The injection controller of  claim 11 , wherein
 the integrated current of the detected current is ∫ t0   ta (EI)dt, and 
 EI is a detected profile of the detected current. 
 
     
     
       13. The injection controller of  claim 12 , wherein
 a correction amount is based on ∫ t0   ta (PKI)dt=∫ t0   tb=(ta+ΔTQ) (EI)dt, 
 tb is the corrected output OFF time of the energization instruction signal, and 
 ΔTQ is the correction amount. 
 
     
     
       14. The injection controller of  claim 1 , wherein
 the integrated current of the detected current is ∫ t0   ta (EI)dt, 
 t 0  is an ideal energization start time, 
 ta is an ideal energization end time, and 
 EI is a detected profile of the detected current. 
 
     
     
       15. An injection controller that injects fuel from a fuel injection valve, the injection controller comprising:
 a control unit configured to output an energization instruction signal for controlling the fuel injection valve; and 
 a current detector configured to detect an electric current flowing in the fuel injection valve, 
 wherein 
 the control unit corrects an output OFF time of the energization instruction signal based on a difference between (i) an integrated current of an ideal current profile and (ii) an integrated current of the detected current detected by the current detector, 
 the integrated current of the ideal current profile is a first ideal charge amount flowing into the fuel injection valve during a first continuous time period within a single ideal fuel injection cycle, 
 the integrated current of the ideal current profile is ∫ t0   ta (PI)dt, 
 t 0  is an ideal energization start time, 
 ta is an ideal energization end time, 
 PI is the ideal current profile, 
 the integrated current of the detected current is ∫ t0   ta (EI)dt, and 
 EI is a detected profile of the detected current. 
 
     
     
       16. An injection controller that injects fuel from a fuel injection valve, the injection controller comprising:
 a control unit configured to output an energization instruction signal for controlling the fuel injection valve; and 
 a current detector configured to detect an electric current flowing in the fuel injection valve, 
 wherein 
 the control unit corrects an output OFF time of the energization instruction signal based on a difference between (i) an integrated current of an ideal current profile and (ii) an integrated current of the detected current detected by the current detector, 
 the integrated current of the ideal current profile is a first ideal charge amount flowing into the fuel injection valve during a first continuous time period within a single ideal fuel injection cycle, 
 the integrated current of the detected current is ∫ t0   ta (EI)dt, 
 t 0  is an ideal energization start time, 
 ta is an ideal energization end time, and 
 EI is a detected profile of the detected current.